The ideas behind the books

Time Travel

We have to face up to the fact that there is probably no such thing as time
travel, at least as described in stories: it is not possible now, nor can it ever become possible in the future.
We can prove that to ourselves simply by answering the question: 'where are
they all, the time travellers?' If time travel were ever to become possible in
the remote future, we would all, right now, be crowded out by people milling
around in silver catsuits trying to mess about with the space-time
continuum.

But it does happen all the time in books. It's an enticing
fantasy - to be able to actually go back and live among people from past times
to see what it was really like, and with the benefit of hindsight, to perhaps
change a few things for the better. No matter what the fantasy, though,
writers must create for us a world which stands up to a certain amount of
scrutiny.

The major issue is to decide whether your characters can
change the past. Obviously some small changes occur simply by travelling back
in time. In 'An Angel for May' for instance Tam steals some clothes from a
washing line in wartime England because his own clothes call too much
attention to himself. Nothing significant stems from this so it is allowed to
pass, although we only know with hindsight that this act of theft is
insignificant. However, when Tam realises that his friends are in danger he
tries to travel back in time for the sole purpose of warning them about the
fire. The implications of allowing someone to live who might otherwise have
died are too great though and Melvin Burgess backs away, so Tam doesn't work
out how to pass through the portal until it is too late. Of course, if he had
more control over the portal, with time travel there is no such thing as
arriving too late. But I do like the way Melvin Burgess uses the time travel
experience to change the present and future. When Tam finally returns to the
present he understands why things are how they are and sets about changing
them.

What you can permit your characters to do while they are time
travellers obviously has a huge impact on the way you tell your story. In 'The
Sterkarm Handshake' Susan Price wants to create a major interference with the
path of history and achieves this simply by asking us not to worry about the
implications:

Of course, she was a dimension removed from her
own world, so this wasn't the 16th century of her own time-line - if she'd
understood the scientific explanations at all correctly. But, she'd been
assured, the two dimensions were so close, there was no essential
difference.

So, once she's told us that anything is possible
in this dimension, we go on to see settlers from the 21st century going to
live 16th side, major 21st century surgery saving the lives of 16th siders and
plenty of other dramatic events. It doesn't really matter what the rules are
as long as they work for the book.

If time travel is in fact possible,
it seems to me the only way it could work is for the traveller to find himself
transported to a place where he can neither be seen by, nor interact in any
way with the locals. He is merely a watcher. A witness to the facts. That may
explain where all those silver catsuited people are – they're peering
invisibly over your shoulder while you read these notes...